The Percophidae, duckbills, are a family of

percomorph Percomorpha () is an extremely large and diverse clade of ray-finned fish. With more than 17,000 known species (including Scombroidei, tuna, Syngnathiformes, seahorses, gobies, Cichlidae, cichlids, flatfish, Labridae, wrasse, Perciformes, perches ...

fishes, from the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Trachiniformes Trachiniformes is an Order (taxonomy), order of Percomorpha, percomorph bony fish, whose contents are traditionally placed in suborder Trachinoidei of Perciformes. However, Trachiniformes is recovered as polyphyletic in recent large scale molec ...

, found in tropical and subtropical waters of the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

and

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

s and in the southwestern and southeastern

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

. They are small fishes: the largest species, the Brazilian flathead, ''Percophis brasiliensis'', grows up to about , but to is more typical. A few species are fished commercially, including the Brazilian flathead.

Taxonomy

Percophidae was first proposed as a family in 1839 by the English

zoologist Zoology ( , ) is the scientific study of animals. Its studies include the structure, embryology, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. Zoology is one ...

William Swainson William Swainson Fellow of the Linnean Society, FLS, Fellow of the Royal Society, FRS (8 October 1789 – 6 December 1855), was an English ornithologist, Malacology, malacologist, Conchology, conchologist, entomologist and artist. Life Swains ...

as a

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

of the

Percidae The Percidae are a family of ray-finned fish, part of the order Perciformes, which are found in fresh and brackish waters of the Northern Hemisphere. The majority are Nearctic, but there are also Palearctic species. The family contains nearly 250 ...

. The 5th edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' classifies this family within the

and divides it into the subfamilies Bempropinae, Henerocoetinae and Percophinae. Other authorities recognise thie family Percophinidae as being

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

with only ''Percophis'' classified within it and placed in the suborder Percophoidei of the order

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

. They classify the other two subfamilies as families, the

Bembropidae Bembropidae is a family of ray-finned fishes in the order Perciformes. Genera There are two genera within the family: * '' Bembrops'' Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austria ...

within the monotypic suborder, Bembropoidei, of Perciformes, and the

Hemerocoetidae Hemerocoetidae is a family of percomorph ray-finned fishes belonging to the order Acropomatiformes. Genera The following genera are included within the Hemerocoetinae: * '' Acanthaphritis'' Günther, 1880 * '' Dactylopsaron'' Parin, 1990 * '' ...

which they classify within the order

Acropomatiformes The Acropomatiformes or Pempheriformes are an order of fish from the group of perch relatives Percomorpha. The relationship of the families assigned to the Acropomatiformes is based on molecular biological studies and is not yet supported by mor ...

, the Oceanic basses.

Subfamilies and genera

The family Percophidae is divided into three

subfamilies In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zool ...

* Subfamily Bembropinae ** ''

Bembrops ''Bembrops'' is a genus of ray-finned fish, it is the type genus of the family Bembropidae. Species The following species are classified as members of the genus ''Bembrops'': * '' Bembrops anatirostris'' Ginsburg, 1955 * '' Bembrops cadenati' ...

'' ** ''

Chrionema ''Chrionema'' is a genus of ray-finned fish from the family Bembropidae Bembropidae is a family of ray-finned fishes in the order Perciformes. Genera There are two genera within the family: * '' Bembrops'' Steindachner Franz Steindachner ...

'' *Subfamily Hemerocoetinae ** ''

Acanthaphritis ''Acanthaphritis'' is a genus of ray-finned fish which are part of the family Hemerocoetidae. They have an Indo-Pacific distribution. Species There are four recognised species in ''Acanthaphritis'': * ''Acanthaphritis barbata'' (Okamura & Kishi ...

'' ** ''

Dactylopsaron ''Dactylopsaron'' is a monotypic genus of ray-finned fish from the family Hemerocoetidae. The only species in the genus, ''Dactylopsaron dimorphicum'' is found in the eastern South Pacific on the Salas y Gomez ridge and the adjacent part of the ...

'' ** ''

Enigmapercis ''Enigmapercis'' is a genus of ray-finned fish which are part of the family Hemerocoetidae. They have an Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or ...

'' ** ''

Hemerocoetes ''Hemerocoetes'' is a genus of ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because o ...

'' ** ''

Matsubaraea ''Matsubaraea'' is a monotypic genus of ray-finned fish from the family Hemerocoetidae. The only species in the genus, ''Matsubaraea fusiforme'' is found in the western Pacific in the waters around Japan, Thailand and the Philippines on sandy sub ...

'' ** ''

Osopsaron ''Osopsaron'' is a genus of hemerocoetid ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so calle ...

'' ** ''

Pteropsaron ''Pteropsaron'' is a genus of ray-finned fish in the family Hemerocoetidae Hemerocoetidae is a family of percomorph ray-finned fishes belonging to the order Acropomatiformes. Genera The following genera are included within the Hemerocoetinae: ...

'' ** ''

Squamicreedia ''Squamicreedia'' is a genus of ray-finned fishes from the family Hemerocoetidae. It is endemic to waters with sandy sea beds off northern Australia. It is a monotypic genus Genus (; : genera ) is a taxonomic rank above species and below fam ...

'' * Subfamily Percophinae ** '' Percophis''

Timeline of genera

ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-65.5 till:10 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:5 start:-65.5 ScaleMinor = unit:year increment:1 start:-65.5 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -65.5 till: -55.8 color:paleocene text:

Paleocene The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), ...

from: -55.8 till: -33.9 color:eocene text:

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

from: -33.9 till: -23.03 color:oligocene text:

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

from: -23.03 till: -5.332 color:miocene text:

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text:

Pleist. The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -65.5 till: -23.03 color:paleogene text:

Paleogene The Paleogene Period ( ; also spelled Palaeogene or Palæogene) is a geologic period and system that spans 43 million years from the end of the Cretaceous Period Ma (million years ago) to the beginning of the Neogene Period Ma. It is the fir ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:eocene bar:NAM1 from: -37.2 till: 0 text:

color:oligocene bar:NAM2 from: -33.9 till: 0 text:

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -65.5 till: -55.8 color:paleocene text:

from: -55.8 till: -33.9 color:eocene text:

from: -33.9 till: -23.03 color:oligocene text:

from: -23.03 till: -5.332 color:miocene text:

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text:

from: -0.0117 till: 0 color:holocene text: H. bar:era from: -65.5 till: -23.03 color:paleogene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

Characteristics

The species in the family Percophidae are elongated,

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...

fishes with an anteriorly depressed head, a broad flat snout which gives rise to the

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...

duckbills. The mouth is large with a

prognathous Prognathism is a positional relationship of the mandible or maxilla to the skeletal base where either of the jaws protrudes beyond a predetermined imaginary line in the coronal plane of the skull. In the case of ''mandibular'' prognathism (nev ...

lower jaw and exposed

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

. They have large closely placed eyes. There are two spines on the opercula and one on subopercula. They have tiny conical teeth on the mandibles and on the

vomer The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

and

palatine A palatine or palatinus (Latin; : ''palatini''; cf. derivative spellings below) is a high-level official attached to imperial or royal courts in Europe since Roman Empire, Roman times.

bones. There are two

dorsal fins A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found i ...

an anterior dorsal fin with 6 slender spines and a posterior dorsal fin with 13 to 18 soft rays, the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

s have 1 weak spine and 5 branched rays and these are positioned anteriorly to the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s with their bases widely separated. The

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

has only 15 to 25 soft rays and the pectoral fins have between 20 and 28 rays. They body is covered in

ctenoid A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...

scales and the

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelia ...

curves underneath the anterior dorsal fin to below the middle of the flank with the 2 or 3 scales nearest the head being keeled. They are generally brownish in colour with indistinct dark blotches along the body. They are

, carnivorous fish which are found at depths of . They are relatively small and uncommon and are of no interest to fisheries.

References

* * {{Authority control Percomorpha Marine fish families Polyphyletic groups